$A$ rough vertical board has an acceleration $a$ so that a $2 \ kg$ block pressing against it does not fall. The coefficient of friction between the block and the board should be

Why do we feel dizzy when riding a giant wheel (Ferris wheel) rotating in a vertical plane?

$A$ man of weight $W$ is standing on a lift which is moving downward with an acceleration $a$. The apparent weight of the man is

In the given arrangement,all surfaces are smooth. What acceleration $a$ should be given to the system (block $M$) so that the block $m_2$ does not slide down?

Inside a horizontally moving box,an experimenter finds that when an object is placed on a smooth horizontal table and is released,it moves with an acceleration of $10\,m/s^2$. In this box,if a $1\,kg$ body is suspended with a light string,the tension in the string in the equilibrium position (with respect to the experimenter) will be $.........\,N$. (Take $g = 10\,m/s^2$)

$A$ person standing on a spring balance inside a stationary lift measures $60 \, kg$. The weight of that person if the lift descends with a uniform downward acceleration of $1.8 \, m/s^{2}$ will be $_{-} N$. $[g = 10 \, m/s^{2}]$